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Who gets PTSD and who doesn’t? Perhaps half of all adult Americans will experience a traumatic event at some time in their lives, but studies estimate that only 25% of such individuals will develop PTSD, resulting in a lifetime prevalence rate of about 8%.1 Now it may be possible not only to identify those at high risk for developing PTSD but also to treat them before they get PTSD, and thus, in concept, to prevent them from getting PTSD.